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这段代码杂用？有啥用？能干什么？
最近在做一个图片网，你说能干嘛用呢？？呵呵。。。
一张高清图，最少都是一MB以上的，看了这个之后，你还在用原来的，只保存一张图片？？？
那你显示列表页的时候，不卡死了才怪了，一个页面显示60张图片，一张图片来个不多，1MB，整个列表下来是60MB。。。老大，强悍。。。牛B哇。。。嘿嘿
搞啥？不搞啥，切出来后，在搞，显示缩略图，弄成几十K的大小，显示一张比例为800*600的图，用到详细页面去，在搞个原图，用来点击查看原图用，这样就不用当心了吧？速度自然就上去了
View Code
using System.IO;using System.Drawing;/// <summary> /// 图片上传 /// </summary> /// <param name="uname">用户名，用于生成图片名称</param> /// <param name="file">HttpPostedFile</param> /// <returns>图片路径</returns> public string[] ImgUpLoad(string uname, HttpPostedFile file) { string[] returnImg = new string[3]; int intThumbWidth = 160; int intThumbHeight = 160; string sFilename = ""; HttpPostedFile myFile = file; int nFileLen = myFile.ContentLength; if (nFileLen == 0) return null; //获取upImage选择文件的扩展名 string extendName = System.IO.Path.GetExtension(myFile.FileName).ToLower(); //判断是否为图片格式 if (extendName != ".jpg" && extendName != ".jpge" && extendName != ".gif" && extendName != ".bmp" && extendName != ".png") return null; byte[] myData = new Byte[nFileLen]; myFile.InputStream.Read(myData, 0, nFileLen); sFilename = System.IO.Path.GetFileName(myFile.FileName); //生成目录名称 string dirName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString(); if (!Directory.Exists(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/ShowPhoto/" + dirName + "/"))) { Directory.CreateDirectory(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/ShowPhoto/" + dirName + "/")); } //----生成未处理原图存放目录名称 string dirNameSrc = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString(); if (!Directory.Exists(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/Photo/" + dirNameSrc + "/"))) { Directory.CreateDirectory(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/Photo/" + dirNameSrc + "/")); } DateTime dtime = DateTime.Now; //生成图片文件名称 string fileName = dtime.Year.ToString() + dtime.Month.ToString() + dtime.Day.ToString() + dtime.Hour.ToString() + dtime.Minute.ToString() + dtime.Second.ToString() + dtime.Millisecond.ToString() + extendName; fileName = uname + fileName; //处理完显示图片 string savePath = "~/PhotoUploadFile/ShowPhoto/" + dirName + "/"; string dirPath = dirName + "/"; //----未处理原图路径与目录 string savePathSrc = "~/PhotoUploadFile/Photo/" + dirNameSrc + "/"; string dirPathSrc = dirNameSrc + "/"; //----保存未处理原图 System.IO.FileStream newFileSrc = new System.IO.FileStream(System.Web.HttpContext.Current.Server.MapPath(savePathSrc) + fileName, System.IO.FileMode.Create, System.IO.FileAccess.Write); newFileSrc.Write(myData, 0, myData.Length); newFileSrc.Close(); returnImg[0] = savePathSrc + fileName; //以上为上传原图 try { //原图加载 using (System.Drawing.Image sourceImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(savePathSrc + fileName))) { //原图宽度和高度 int width = sourceImage.Width; int height = sourceImage.Height; int smallWidth; int smallHeight; //获取第一张绘制图的大小,(比较 原图的宽/缩略图的宽 和 原图的高/缩略图的高) if (((decimal)width) / height <= ((decimal)intThumbWidth) / intThumbHeight) { //smallWidth = width/(height/intThumbHeight); smallWidth = width * intThumbHeight / height; smallHeight = intThumbHeight; } else { smallWidth = intThumbWidth; //smallHeight = height/(width/intThumbWidth); smallHeight = height * intThumbWidth / width; } //生成目录名称 dirName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString(); if (!Directory.Exists(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/Thumb/" + dirName + "/"))) { Directory.CreateDirectory(System.Web.HttpContext.Current.Server.MapPath("~/PhotoUploadFile/Thumb/" + dirName + "/")); } dtime = DateTime.Now; savePath = "~/PhotoUploadFile/Thumb/" + dirName + "/"; string dirPath2 = dirName + "/"; //缩略图保存的绝对路径 string smallImagePath = System.Web.HttpContext.Current.Server.MapPath(savePath) + fileName; //新建一个图板,以最小等比例压缩大小绘制原图 using (System.Drawing.Image bitmap3 = new System.Drawing.Bitmap(smallWidth, smallHeight)) { //绘制中间图 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap3)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); g.DrawImage( sourceImage, new System.Drawing.Rectangle(0, 0, smallWidth, smallHeight), new System.Drawing.Rectangle(0, 0, width, height), System.Drawing.GraphicsUnit.Pixel ); } //新建一个图板,以缩略图大小绘制中间图 using (System.Drawing.Image bitmap1 = new System.Drawing.Bitmap(intThumbWidth, intThumbHeight)) { //绘制缩略图 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap1)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); int lwidth = (smallWidth - intThumbWidth) / 2; int bheight = (smallHeight - intThumbHeight) / 2; g.DrawImage(bitmap3, new Rectangle(0, 0, intThumbWidth, intThumbHeight), lwidth, bheight, intThumbWidth, intThumbHeight, GraphicsUnit.Pixel); g.Dispose(); bitmap1.Save(smallImagePath, System.Drawing.Imaging.ImageFormat.Jpeg); returnImg[1] = savePath + fileName; } } } //生成显示图片 ShowPhoto intThumbWidth = 800; intThumbHeight = 600; string equalSavePath = "~/PhotoUploadFile/ShowPhoto/" + dirName + "/"; string showSrcPath = equalSavePath; equalSavePath = System.Web.HttpContext.Current.Server.MapPath(equalSavePath) + fileName; if (((decimal)width) / height <= ((decimal)intThumbWidth) / intThumbHeight) { //smallWidth = width/(height/intThumbHeight); smallWidth = width * intThumbHeight / height; smallHeight = intThumbHeight; } else { smallWidth = intThumbWidth; //smallHeight = height/(width/intThumbWidth); smallHeight = height * intThumbWidth / width; } if (width <= 800 && height <= 600) { smallWidth = width; smallHeight = height; } //if (height < 800 && width < 600) //{ // smallWidth = height; // smallHeight = width; //} //if (width <= 800) { // smallWidth = width; //} //if (height <= 600) { // smallHeight = height; //} //新建一个图板,以最小等比例压缩大小绘制原图 using (System.Drawing.Image bitmap3 = new System.Drawing.Bitmap(smallWidth, smallHeight)) { //绘制中间图 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap3)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); g.DrawImage( sourceImage, new System.Drawing.Rectangle(0, 0, smallWidth, smallHeight), new System.Drawing.Rectangle(0, 0, width, height), System.Drawing.GraphicsUnit.Pixel ); } //新建一个图板,以缩略图大小绘制中间图 using (System.Drawing.Image bitmap1 = new System.Drawing.Bitmap(intThumbWidth, intThumbHeight)) { //绘制缩略图 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap1)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); int lwidth = (smallWidth - intThumbWidth) / 2; int bheight = (smallHeight - intThumbHeight) / 2; g.DrawImage(bitmap3, new Rectangle(0, 0, intThumbWidth, intThumbHeight), lwidth, bheight, intThumbWidth, intThumbHeight, GraphicsUnit.Pixel); g.Dispose(); bitmap1.Save(equalSavePath, System.Drawing.Imaging.ImageFormat.Jpeg); returnImg[2] = showSrcPath + fileName; } } } } } catch (Exception ex) { //出错则删除 //System.IO.File.Delete(System.Web.HttpContext.Current.Server.MapPath(savePath)); throw ex; } return returnImg; }
来源：https://www.cnblogs.com/zhoudemo/archive/2012/01/12/2320288.html